JPH11320954A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably achieve high density and high resolution printing. SOLUTION: A plurality of first control electrodes 37 are arranged in parallel to each other and a plurality of second control electrodes 39 are arranged so as to across the first control electrodes 37. A toner conveying belt 29 carrying toner which is charged at the side of the first control electrodes 37 in a portion between the first and second control electrodes 37, 39 is conveyed in a direction S and a recording medium P is conveyed at the side of the second control electrode in a direction S1 opposite the conveying direction of the belt 29. A predetermined voltage is applied across the first and second control electrodes 37, 39 and a predetermined voltage is generated therebetween so that the toner on the belt 29 is allowed to fly toward the recording medium P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to printing means of digital copiers and facsimile machines, digital printers, plotters, and the like, and forms a toner image on a recording material by causing toner carried on a carrier to fly. To an image forming apparatus.

[0002]

2. Description of the Related Art An image forming apparatus as an information output apparatus such as a digital copying machine, a facsimile apparatus, a computer, a word processor, and a printer, for recording paper or the like based on an image signal output from the image information output apparatus. Various printing methods have been proposed for an image forming apparatus that forms a visible image on a material. For example, a method of flying ink, a method of melting and transferring ink, a method of sublimating ink, and an electrophotographic method have been put to practical use. Among such printing methods, an ink-jet method of ejecting ink, which has a relatively simple structure, is frequently used in accordance with recent demands for higher speed, higher image quality, and lower cost.
However, the ink jet method uses a liquid ink, so that the ink easily bleeds on the recording material, and it is difficult to obtain a high-quality image. In addition, the ink used is easily solidified, and it is difficult to store a large amount of ink, which is not suitable for applications requiring a large amount of printing.

On the other hand, in the printing method using toner, a visually excellent image having a high color tone without blurring can be obtained. Further, it is easy to control the amount of toner forming one pixel, and it is expected that the reproducibility of a grayscale image in a copying machine and the color reproducibility in a color image forming apparatus are improved. Therefore, there has been proposed a direct printing method using a toner flying method in which a simple process of an ink jet method is combined with an image forming method using toner.

Japanese Patent Application Laid-Open No. 52-149021 has a plurality of needle electrodes and a counter electrode provided on a roller-shaped carrier opposed to the needle electrodes, and a recording paper is conveyed between these electrodes. Supplying toner between the counter electrode and the recording paper,
The present invention relates to a technology for forming a toner image according to an image signal by causing toner to fly on a recording sheet by an electric field from a counter electrode to a needle electrode. The positional relationship between the counter electrode and the needle electrode is configured to change sequentially with the rotation of the carrier, and a plurality of sets of needle electrodes are controlled by one set of needle electrodes facing the counter electrode.

Japanese Unexamined Patent Publication No. Sho 54-134629 discloses a toner carrier 1 of a base 3 as shown in FIG.
A high voltage is applied to a stylus 5 provided on one surface on the opposite side to the other, and a plurality of control electrodes 4a provided on the other surface of the base 3 on the toner carrier 1 side at a low voltage in accordance with an image signal. , 4b, 4c,... (Collectively referred to as “control electrodes 4”), the flying electric field of the toner 2 carried on the carrier 1 is controlled to fly the toner on the recording material 6. It has been disclosed.

Japanese Patent Application Laid-Open No. 58-140265 discloses an image carrier in which a toner carrier having a thin layer of a toner on which an electrode pattern is formed in advance and an image carrier are arranged close to each other.
There is disclosed a technique in which an electric field is applied between an electrode pattern of a toner carrier and an image carrier to cause toner to fly on the image carrier according to the electrode pattern of the toner carrier.

Japanese Patent Application Laid-Open No. 1-503221 discloses a method for forming various images with a small number of control electrodes.
There is disclosed a technique of forming a toner image by applying a voltage to wire electrodes arranged in a matrix and applying an electric field to permit or inhibit the passage of toner.

Further, JP-A-6-227022 discloses that
In order to increase the accuracy of the control electrode that controls the passage of toner, and to increase control efficiency and stability, multiple row electrodes,
A plurality of column electrodes and back electrodes intersecting with the row electrodes are arranged in this order, toner is supplied between the row electrodes and the column electrodes, and the recording paper is transported between the column electrodes and the back electrodes. The flying of the toner is controlled by an electric field applied between the electrode and the column electrode.

[0009]

In the image forming apparatus of the flying type, it is required that the toner flies corresponding to at least the pixels, and that the number of control electrodes for controlling the flying and the control voltage are required to be reduced. . In particular, with the rapid development of computers in recent years, with high resolution and high speed, for example, a printing speed of several sheets per minute at a density of 300 pixels or more per inch is required in an image forming apparatus having a relatively low price.

In the above-mentioned Japanese Patent Application Laid-Open No. 52-149022, the carrier provided with the counter electrode is rotated by one rotation between a printing operation using one set of needle electrodes and the next printing operation. It is not suitable for speeding up.

In Japanese Patent Application Laid-Open No. 54-134629, the electrode structure of the toner carrier 1 corresponding to the counter electrode is simplified, and if the toner supply is sufficient, the speed can be increased. However, there is a problem that a sufficient flying amount of the toner cannot be obtained and high-resolution printing cannot be performed. That is, since the electric field formed by the high voltage applied to the stylus 5 is controlled by the control electrode 4 to which the voltage is applied according to the image signal, the arrangement of the stylus 5 and the control electrode 4 depends on the arrangement. The voltage applied to the control electrode 4 is determined. Specifically, in a configuration in which the electric field formed between the stylus 5 and the toner carrier 1 is shielded by the control electrode 4 and the toner 2 flies as shown in FIG. When the width is reduced, the suction force acting on the toner 2 on the toner carrier 1 in the direction of the stylus 5 is reduced, so that a sufficient amount of the toner 2 cannot be caused to fly. Further, since it is difficult to increase the density of the control electrodes 4, it is not possible to increase the printing resolution.

In Japanese Patent Application Laid-Open No. 58-140265, a toner image can be formed at high speed, but printing other than the electrode pattern cannot be performed. Therefore, the use of the device is limited to special uses such as printing of numbers and alphabets.

In Japanese Patent Application Laid-Open No. 1-503221, it is possible to control the flight of toner with a relatively simple configuration using control electrodes in a matrix. However, it is difficult to form the control electrodes in a matrix with high accuracy. It is difficult to increase the resolution. Further, when the resolution is increased, the toner passage area becomes narrow, and a sufficient density of the toner image cannot be obtained.

Further, in Japanese Patent Application Laid-Open No. 6-227022, toner passes through one of the row electrode and the column electrode, which are control electrodes, and is formed by the control electrodes when high resolution is required. The area through which the toner passes becomes extremely narrow, and a sufficient density of the toner image cannot be obtained.

An object of the present invention is to provide an image forming apparatus of a toner flying type capable of stably obtaining high-density and high-resolution printing.

[0016]

According to the present invention, there is provided a first control electrode member comprising a plurality of electrodes, a second control electrode member comprising a plurality of electrodes opposed to the first control electrode, the first and second control electrode members comprising a plurality of electrodes. A toner carrier, which is disposed on the first control electrode member side between the two control electrode members and carries and transports the charged toner; and a dielectric member on the second control electrode member side between the first and second control electrode members. A recording material conveying unit configured to convey a recording material composed of a body, wherein the first control electrode member is provided in the image forming apparatus that forms a toner image on the recording material by flying toner carried by the toner carrier. Are arranged in parallel with each other, and the plurality of electrodes constituting the second control electrode member are arranged in a direction intersecting with the electrode of the first control electrode member, and the toner carrier is transported. Direction and method of transporting the recording material And is an image forming apparatus, characterized in that selected in opposite directions.

According to the present invention, the first control electrode member composed of a plurality of electrodes arranged in parallel with each other and the plurality of electrodes arranged in a direction intersecting the electrodes of the first control electrode member. A toner carrier carrying charged toner is conveyed on the first control electrode member side between the second control electrode member and the recording material opposite to the toner carrier on the second control electrode member side. Conveyed in the direction. By applying a predetermined voltage between the first and second control electrode members and applying a predetermined electric field between the first and second control electrode members, the toner on the toner carrier can fly toward the recording material.

Since the first and second control electrode members for controlling the flight of the toner are not disposed between the toner carrier and the recording material, the adhesion of the toner to the control electrode member can be prevented.
High printing quality can be stably obtained over a long period of time. Further, since the first and second control electrode members can be formed without being restricted by the thickness, it is possible to form them with high precision to obtain high-resolution print quality.
In addition, the second control electrode member is integrally formed with a control circuit, a driver, and the like, so that the assemblability and reliability of the image forming apparatus can be improved.

Further, according to the present invention, a voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage to be applied to the first and second control electrode members are selected. Voltage selecting means for selecting a voltage applied to the second control electrode member and having a polarity opposite to that of the charged toner to set a printing state in which the toner is allowed to fly; And a voltage selection unit for selecting a voltage applied to the control electrode member and having a polarity opposite to that of the charged toner and setting a non-printing state for inhibiting the toner from flying.

According to the present invention, the printing state is determined by applying a voltage having a polarity opposite to that of the charged toner to the second control electrode member, that is, the electrode member on the recording material side. The electric field of the potential that flies toward the material
And between the second control electrode members. In the non-printing state, a voltage having a polarity opposite to that of the charged toner is applied to the first and second control electrode members, and an electric field having a weaker intensity than at the time of printing is applied between the first and second control electrode members. It can be realized by acting. Therefore, the polarity of the voltage power supply applied to the first and second control electrode members can be shared, and an inexpensive image forming apparatus can be realized.

Further, according to the present invention, a voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage to be applied to the first and second control electrode members are selected. Voltage selecting means for selecting a voltage applied to the first control electrode member and having the same polarity as that of the charged toner to set a printing state in which the toner is allowed to fly; A voltage selection unit for selecting a voltage applied to the electrode member and having the same polarity as that of the charged toner, and setting a non-printing state for inhibiting the toner from flying.

According to the present invention, in the printing state, a voltage having the same polarity as that of the charged toner is applied to the first control electrode member on the carrier side, and the toner on the toner carrier flies toward the recording material. It can be realized by applying an electric field of such a potential between the first and second control electrode members.
In the non-printing state, the first and second control electrode members
This can be realized by applying a voltage having the same polarity as that of the charged toner and causing an electric field having a lower intensity than that at the time of printing to act between the first and second control electrode members. Therefore, the polarity of the power source of the voltage applied to the first and second control electrode members can be shared, and an inexpensive image forming apparatus can be realized. Further, since the polarity of the applied voltage is the same as that of the toner, unnecessary adhesion of the toner to each control electrode member can be prevented.

The present invention also provides a voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage for selecting a voltage to be applied to the first and second control electrode members. Selecting means for selecting a voltage applied to the second control electrode member and having a polarity opposite to that of the charged toner, and applying a voltage to the first control electrode member; And a voltage having the same polarity as that of the charged toner is selected to prevent the toner from flying. And a voltage selecting means for setting a non-printing state.

According to the present invention, the printing state is such that a voltage having a polarity opposite to that of the charged toner is applied to the second control electrode member on the recording material side, and the first control electrode member on the toner carrier side is
This is achieved by applying a voltage having the same polarity as the charged toner and causing an electric field having a potential such that the toner on the toner carrier flies toward the recording material between the first and second control electrode members. Can be. The non-printing state is
This can be realized by applying a voltage having the same polarity as that of the charged toner to the first control electrode member to cause an electric field having a weaker intensity than during printing to act between the first and second control electrode members. Therefore, it is possible to obtain the electric field intensity required for printing while suppressing the intensity of the voltage applied to the first and second control electrode members, to reduce the cost for the power supply, and to ensure the high security of the power supply. it can. further,
Since the polarity of the voltage applied to the first control electrode member on the toner carrier side is the same as that of the toner, unnecessary adhesion of the toner to the control electrode member can be prevented.

Further, according to the present invention, the electrode of the first control electrode member is formed so as to extend in a direction perpendicular to the conveying direction of the toner carrier, and the electrode of the second control electrode member is formed of the first control electrode member.
It is characterized in that it is formed to extend at an intersection angle θ in the range of 45 ° <θ <90 ° with respect to the electrode of the control electrode member.

According to the present invention, the electrode of the second control electrode member is set at 45 ° with respect to the direction in which the electrode of the first control electrode member extends, that is, the direction orthogonal to the conveying direction of the toner carrier.
By arranging at an intersection angle θ in the range of <θ <90 °, printing with an optimum resolution can be obtained. θ is 45
When the temperature is less than or equal to °, the range of the electric field applied to the toner on the toner carrier becomes narrow, and a sufficient amount of toner does not fly, and only low-resolution printing can be obtained. Note that the distance between the control electrode members becomes longer as θ approaches 90 °, and it becomes difficult to maintain the distance between the control electrode members with high accuracy. It is particularly preferable that the intersection angle θ is around 63 °, at which a sufficient amount of toner can be obtained and the distance between the control electrode members can be maintained with high accuracy.

According to the present invention, there are provided a first drive means for selectively applying the drive voltage at a predetermined cycle to a plurality of electrodes constituting the first control electrode member, and a second drive electrode member. And a second driving means for applying a driving voltage or a non-driving voltage to the plurality of electrodes.

According to the present invention, a drive voltage is selectively applied to a plurality of electrodes constituting the first control electrode member at a predetermined cycle, and a drive voltage or a drive voltage is applied to the plurality of electrodes constituting the second control electrode member. By applying the non-driving voltage, the charge uniformly acts on the toner to be conveyed. Therefore, stable printing can be performed.

Further, when the first control electrode member disposed on the toner carrier side is attached to a detachable toner supply section for replenishment and maintenance of toner, the number of control electrodes is reduced, so that reliability is reduced. improves. Further, when the second control electrode member disposed on the recording material side is attached to the main body of the image forming apparatus, a predetermined voltage is applied to the control electrode member according to an image signal on the electrode mounting substrate. It can be formed integrally with a driver including an integrated circuit to be applied.

Further, according to the present invention, the surface electrical resistance of the toner carrier is selected in the range of 1 × 10 ⁶ Ω · cm to 1 × 10 ¹² Ω · cm, and the toner carrier and the first control electrode member Are arranged in contact with each other, and the first driving means
The driving voltage is sequentially applied to a plurality of electrodes constituting the control electrode member from a direction opposite to a conveying direction of the toner carrier.

According to the present invention, the position accuracy of the carrier can be improved by bringing the toner carrier into contact with the first control electrode member, and the toner carried on the recording material by the run-out or vibration of the carrier can be improved. Contact can be prevented.

Further, since the surface electric resistance of the toner carrier is selected to be a relatively high value, the electrostatic attraction force of the toner to the carrier increases due to the charging by the continuous rotation of the carrier, and the toner flies. This can prevent the disadvantage that the printing property is lowered and the printing density is lowered. By setting the surface electric resistance of the toner carrier to 1 × 10 ⁸ Ω · cm or more, a voltage corresponding to the applied voltage is applied to the toner carrier, and a current flowing through the first control electrode member is generated by heat generation or the like. The influence can be suppressed to such an extent that the influence is not caused, and the charging of the toner carrier due to friction or the like can be prevented.

Further, by applying a drive voltage to the plurality of electrodes constituting the first control electrode member sequentially from the direction opposite to the direction of transport of the toner carrier, the apparent transport speed of the toner can be increased. And high-speed printing becomes possible. However, the surface electric resistance of the toner carrier is 1 × 10 ¹²
If the resistance is Ω · cm or more, the ability to follow the applied voltage of the carrier is reduced, so that it is not suitable for high-speed printing.

Further, the present invention is characterized in that the period of the printing state in which the toner is allowed to fly includes a period in which a driving voltage is applied to the first and second control electrode members and a period in which a non-driving voltage is applied. I do.

According to the present invention, since the toner flying toward the recording material is not affected by the next printing electric field, the printing position is deviated by the influence of the printing electric field and the printing position is shifted. Can be suppressed.

The period during which the non-driving voltage is applied to the first and second control electrode members is a period during which the electric field strength for the toner to fly toward the recording material is at a minimum. Are not deflected. The period in which the drive voltage is applied to the first and second control electrode members is a period in which the electric field intensity is maximum. By shifting, the rush current at the time of voltage switching can be dispersed, the capacity of the power supply can be reduced, and the wiring pattern can be miniaturized.

In the present invention, the transition of the driving voltage applied to the first control electrode member to the non-driving voltage is performed before the transition of the driving voltage applied to the second control electrode member to the non-driving voltage. It is characterized by the following.

According to the present invention, since the drive voltage is applied to the second control electrode member longer than to the first control electrode member, the flying toner reliably reaches the recording material. Therefore, it is possible to suppress toner scattered in the conveying direction of the recording material.

According to the present invention, the transition of the non-drive voltage applied to the first control electrode member to the drive voltage is performed before the transition of the non-drive voltage applied to the second control electrode member to the drive voltage. It is characterized by the following.

According to the present invention, an electric field acts on the toner before the toner flies, so that the voltage can be applied to the second control electrode member and the toner can fly smoothly. Therefore, printing with a uniform density in the plane can be performed.

Further, the present invention is characterized in that a convex portion toward the first control electrode member is formed on an electrode of the second control electrode member which intersects with the electrode of the first control electrode member.

According to the present invention, it is possible to form a pixel having an area equal to that of the convex portion regardless of the width of the electrode of the second control electrode member. Therefore, even when high-resolution printing is performed, the width of the second control electrode member itself can be formed to be large, so that workability and reliability can be improved.

Further, the present invention is characterized in that an adhesive is applied to the surface of the recording material on the toner carrier side.

According to the present invention, it is possible to prevent repulsion and scattering that occur when the toner lands on the recording material, and to prevent the toner from falling off before the fixing step, thereby enabling high-quality printing.

When silicone oil is used as the adhesive, it is possible to improve the adhesion of the toner to the recording material in the fixing section and the releasability from the fixing roller.
Examples of the adhesive that can be used include liquids having an oily viscosity such as silicone oil and glue such as glue. The same effect can be obtained even with a liquid having almost no viscosity.

Further, according to the present invention, there are provided a plurality of first control electrode members each comprising a plurality of electrodes, a plurality of second control electrode members each comprising a plurality of electrodes and opposed to each of the first control electrode members. A plurality of toner carriers each of which is disposed on the first control electrode member side between the first and second control electrode members and carries and conveys charged toner;
A single transfer belt made of a dielectric commonly disposed on the side of the second control electrode member between the control electrode members, and a recording material conveying means for conveying the recording material in contact with the transfer belt; In an image forming apparatus in which a toner carried on a toner carrier is respectively fly and transferred once onto a transfer belt and then transferred to a recording material to form a toner image, a plurality of electrodes constituting each first control electrode member are provided. Are arranged in parallel with each other, and a plurality of electrodes constituting each second control electrode member are arranged in a direction intersecting the electrodes of the opposing first control electrode member, and the transport direction of each toner carrier and the The image forming apparatus is characterized in that the transfer direction of the transfer belt is selected to be opposite to each other.

According to the present invention, for example, toner of different colors is transferred to a transfer belt and then transferred to a recording material, thereby enabling color printing. Also in this case, high print quality can be stably obtained over a long period of time.
In addition, the control electrode member can be formed with high precision to obtain high-resolution printing quality, and the first and second control electrode members can be integrally formed with a control circuit, a driver, and the like to improve the assemblability of the image forming apparatus. And reliability can be improved.

Since the toner image is formed on the recording material via the transfer belt, it is particularly effective to apply an adhesive such as silicone oil to the recording material to improve the fixing property.

[0049]

FIG. 1 is a sectional view showing a printer 11 equipped with an image forming apparatus according to an embodiment of the present invention. The printer 11 forms a toner image on a recording material by causing toner to fly according to a predetermined image signal. In the present embodiment, an example in which a negatively charged toner is used will be described. However, a positively charged toner may be used. In this case, the polarities of various voltages applied for image formation may be set as appropriate. The printer 11 generally includes the sheet feeding unit 1.
2, a toner supply unit 13, a printing unit 14, a fixing unit 15, and a control unit 16.

The paper feed unit 12 is provided upstream of the printing unit 14 in the recording material transport direction. The paper supply unit 12 includes a paper supply cassette 21 that stores the recording material, a pickup roller 22 that supplies the recording material from the paper supply cassette 21, and transports the supplied recording material to the printing unit 14 according to the timing of printing. And a pair of registration rollers 23. The recording material is conveyed in a direction S1 from the paper feeding unit 12 to the printing unit 14.

As shown in FIG. 2, the toner supply unit 13 for supplying the toner to the printing unit 14 includes a toner storage tank 24 for storing the toner T, and the toner T in the toner storage tank 24 is agitated. A stirring roller 25 for preventing deviation, a belt-shaped toner transport belt 29 that is stretched over a plurality of (in this embodiment, three) rollers 26, 27, and 28 and that carries and transports the toner T, is disposed to face the roller 26. Supply roller 3 for supplying toner T to toner transport belt 29
0, and the toner T carried on the toner conveying belt 29
And a doctor blade 31 for applying a predetermined charge to the toner and regulating the layer thickness of the toner T. The toner transport belt 29 has a direction S opposite to the recording material transport direction S1.
2 is transferred. The doctor blade 31 is provided on the upstream side in the transport direction of the toner transport belt 29 with respect to the printing unit 4, and is provided so as to press against the toner transport belt 29 with a predetermined force.

As the toner T, for example, particles mainly composed of styrene acrylic resin and having a diameter of about 10 μm are used. A negative charge is applied to the toner T by stirring and transport near the doctor blade 31 and the toner supply roller 30.

The conveying speed of the toner conveying belt 29 in the conveying direction S2 is, for example, 60 mm / s on its surface.
ec. Irregularities of several μm are formed on the surface of the toner transport belt 29, and the toner T is pressed against the irregularities by the doctor blade 31. by this,
The toner transport belt 29 carries the toner T on its outer peripheral surface.

As shown in FIGS. 3 and 4, the printing section 14 includes a first control electrode member 32 having a plurality of first control electrodes 37 and a second control electrode member 33 having a plurality of second control electrodes 39. It is comprised including. The first control electrode member 32 and the second control electrode member 33 are arranged to face each other. The toner transport belt 29 includes a control electrode member 3
It is arranged on the first control electrode member 32 side between 2 and 33.
The recording material P is transported on the second control electrode member 33 side. The plurality of first control electrodes 37 of the first control electrode member 32 are arranged in parallel with each other, and the plurality of second control electrodes 39 of the second control electrode member 33 are arranged in a direction crossing the first control electrode 37. .

By applying a voltage to the second control electrode 39 in accordance with the image signal, the first control electrode 37 is applied to the second control electrode 39 between the second control electrode 39 and the first control electrode 37. Apply a heading electric field. Accordingly, the toner T carried on the toner transport belt 29 flies toward the recording material P.

The recording material P is conveyed in close contact with the second control electrode member 33 by the suction force of the fans 34 and 35.

The fixing unit 15 is disposed downstream of the printing unit 14 in the recording material conveyance direction. The fixing unit 15 fixes the toner image printed on the recording material P in the printing unit 14 by heating and pressing the toner image on the recording material P. Fixing unit 15
Is a heating roller 4 as shown in FIGS.
0, a pressure roller 42 disposed opposite to the roller 40
And a temperature sensor 43 for detecting the surface temperature of the heating roller 40.

The heating roller 40 is realized by a 2 mm-thick aluminum tube containing a heater 41 such as a halogen lamp, and the surface temperature is maintained at, for example, 150 ° C. The pressure roller 42 is realized by, for example, a roller made of silicone resin. Each of the rollers 40 and 42 is applied with a load of 2 kg, for example, by a spring (not shown) on the shaft of each roller so as to sandwich and press the recording material P.

In this embodiment, an example of the fixing unit 15 for fixing a toner image by heating and pressing will be described. However, fixing may be performed only by heating or only pressing. The printer 11 may include a discharge roller (not shown) for discharging the fixed recording material P to the outside of the printer 11, a discharge tray for receiving the discharged recording material P, and the like.

The control unit 16 controls the overall operation of the printer 11, and as shown in FIG. 5, a CPU (central processing unit) 44, a voltage application unit 45, a switching unit 46, a row electrode driver 47 and a column electrode driver. 48.
The CPU 44 controls the switching operation of the switching unit 46 so that the voltage applied from the voltage application unit 45 to the first control electrode 37 via the row electrode driver 47 and to the second control electrode 39 via the column electrode driver 48. Control the applied voltage.

The CPU 44 is provided with respect to the paper supply unit 12 and detects the result of the paper supply sensor 49 for detecting that the recording material P has been supplied, and the fact that the fixed recording material P has been discharged. The detection result of the paper discharge sensor 50 for detecting is provided. The CPU 44 controls the operation of each of the drive units 51 to 55 based on these detection results, and
2. Control the drive timing of the registration roller 23, the heating roller 40, the pressure roller 42, and the toner transport belt 29. Further, the timing of voltage application to each of the electrodes 37 and 39 is controlled. Further, the drive timing of the fans 34 and 35 is controlled.

Further, the detection result of the temperature sensor 43 is given to the CPU 44, and based on the detection result, the CPU 44
Controls the on / off operation of the heater 41 so that the surface temperature of the heating roller 40 becomes a predetermined temperature.

In the printing unit 14, the distance between the base 36 of the first control electrode member 32 and the base 38 of the second control electrode member 33 is determined by the amount of the toner T carried on the toner transport belt 29 and the recording material P. The thickness is selected so as not to make direct contact, and is appropriately set according to the layer thickness of the carried toner T, the thickness of the recording material P, the applied voltage, and the like.

For example, the distance between the surface of first control electrode 37 of first control electrode member 32 and the surface of second control electrode 39 of second control electrode member 33 is set to 1 mm. Alternatively, the distance is set to 300 μm. Further, the thickness of the toner transport belt 29 is 30 μm, and the layer thickness of the toner T carried on the toner transport belt 29 is 25 μm.
If the thickness of the recording material P is set to 100 μm, the distance is set to 145 μm.

Each first control electrode 37 has a width of 500 μm, the gap between adjacent electrodes is set to 500 μm, and a predetermined voltage is selectively applied by the row electrode driver 47. Further, a predetermined voltage is selectively applied to the second control electrode 39 by the column electrode driver 48 according to the image signal.

In the printing state in which the toner T flies, for example, when −200 V is applied to the first control electrode 37 and +300 V is applied to the second control electrode 39, the voltage from the first control electrode 37 to the second control electrode 39 increases. An electric field of 0.7 kV / mm is generated. Therefore, the toner T carried on the toner transport belt 29 flies toward the recording material P, and a toner image is formed on the recording material P. The toner T is held on the recording material by the action of electrostatic attraction due to the charge of the toner T and catching due to irregularities on the surface of the recording material P.

On the other hand, in a non-printing state where the toner T does not fly, for example, -200 V is applied to the first control electrode 37,
When the second control electrode 39 is set to 0V, an electric field of 0.7 kV / mm is generated from the first control electrode 37 to the second control electrode 39. At this electric field intensity, the toner does not fly toward the recording material P, but is held by the toner transport belt 29. Therefore, no toner image is formed. In addition, each electrode 37, 39
Is appropriately determined according to the characteristics of the toner and the printing speed.

Hereinafter, features of the printer 11 according to the first embodiment will be described with reference to first to twelfth examples. In the first embodiment, the first control electrodes 37 are arranged in parallel with each other, the second control electrodes 39 are arranged in a direction crossing the first control electrodes 37,
The conveyance direction S2 of the toner conveyance belt 29 and the conveyance direction S1 of the recording material P are selected to be opposite to each other.

When an image signal is given to the CPU 44 from a host computer or the like (not shown), the CPU 44 separates the image signal into a control signal for determining a printing start timing, a size of a recording material, and the like, and an image data signal. next,
The pickup roller 22 is driven to rotate by the print start signal, and conveys the recording material P stored in the paper feed cassette 21 until it comes into contact with the registration roller 23. Here, the sheet cassette 21 is provided with a sensor (not shown) for detecting the presence or absence of the recording material P in the cassette 21, and the pickup roller 22 is driven by the sensor when the recording material P is present. Triggered on detection.

Next, when the registration roller 23 is driven to rotate at a constant speed, the recording material P
4 and 35, the second control electrode member 32
It is transported in close contact with. The printing operation is started in synchronization with the start of the rotation operation of the registration roller 23. The recording material P is conveyed from a state in which it is in contact with the registration roller 23, and the recording material P
Can be printed at a position of a predetermined length from the leading end of the image.

FIG. 6 is a diagram showing the first and second control electrodes 37 and 39 of the first embodiment. As shown in FIG. 6A, the first control electrodes 37a, 37b,... (Collectively, “first control electrodes 37”) have a width of 120 μm and are orthogonal to the recording material conveyance direction S1. Are arranged in the direction of The second control electrodes 39a, 39b, 39c,... (To be collectively referred to as “second control electrodes 39”) have a width of 120 μm and have an angle of 6 ° with respect to the recording material conveyance direction S1, and The control electrodes 37 are arranged so as to intersect. The first control electrode 37 and the second control electrode 39 are opposed to each other with a distance of 300 μm.

Here, a voltage of −200 V is applied to the first control electrode 37 for 1000 μsec, and +3 V is applied to the second control electrode 39.
A voltage of 00 V is applied for 300 μs, and as shown in FIGS. 6B and 6C, the toner transport belt 29 is transported at a speed of 50 mm / sec in the direction S2, and the recording material P
It is transported in the direction S1 at a speed of 0 mm / sec. As a result, a circular toner image having a diameter of 120 μm was formed on the recording material P.

According to the first embodiment, the toner transport belt 2
9 which controls the flight of the toner T between the recording material P and the recording material P;
In addition, since the second control electrodes 37 and 39 are not provided, the adhesion of the toner T to the control electrodes 37 and 39 can be prevented, and high print quality can be stably obtained over a long period of time.
Further, as shown in FIG. 7, since the second control electrode member 33 can be formed without being restricted by the thickness, it is possible to form the second control electrode member 33 with high precision and obtain high-definition printing quality. Further, the second control electrode member 33 is connected to the control circuit 56,
By being integrally formed with the driver and the wiring 57, the assemblability and reliability of the printer 11 can be improved.

The second embodiment is characterized in that the polarity of the voltage applied to each of the control electrodes 37 and 39 is selected.
This is the same as the embodiment. The first control electrode 37 is set to 0V.
Or, to selectively apply a voltage of +300 V,
Further, the second control electrode 39 is set to 0 V, or +500
The switching unit 46, the row electrode driver 47, and the column electrode driver 48 so as to selectively apply the voltage of V
Control.

Here, by applying +500 V having a polarity opposite to that of the toner T to the second control electrode 39 and setting the first control electrode 37 to 0 V, the toner T flies and the recording material P
, A toner image was formed. Further, when +500 V having a polarity opposite to the toner T is applied to the second control electrode 39 and +300 V having a polarity opposite to the toner T is applied to the first control electrode 37, the toner T does not fly and the recording material P No toner image was formed.

According to the second embodiment, a printing state and a non-printing state can be realized by applying a voltage having the above-mentioned polarity. Therefore, the first and second control electrodes 3
The polarity of the power source of the voltage applied to the power supplies 7 and 39 can be shared, and the inexpensive printer 11 can be realized.

FIG. 8 shows the first and second control electrodes 37, 3
9 and the recording material P
9 is a graph showing a relationship with the print density. Here, the electric field is a value on a flat plate when applied for one second. When a toner image of about 100 μm is formed with a voltage application time of about several hundred μsec as in the second embodiment, a completely non-printing state is obtained when the print density is 0.2 or less. On the other hand, when the print density is 0.5 or more, a print state in which a sufficient amount of toner flies is obtained. Therefore, when the distance between the first and second control electrodes 37 and 39 is 300 μm, a non-printing state is set when the potential difference is 300 V or less, and a printing state is set when the potential difference is 500 V or more. From this, when the non-driving voltage is applied, the first
By applying a voltage having a polarity opposite to that of the toner T to both the second control electrodes 37 and 39, the toner T
Of the recording material P to the recording material P can be controlled.

The third embodiment is also similar to the first embodiment except that the polarity of the voltage applied to each of the control electrodes 37 and 39 is selected. The CPU 44 sets the first control electrode 37 to 0 V or selectively applies a voltage of -500 V, and sets the second control electrode 39 to 0 V or selectively applies a voltage of -200 V. Is the switching unit 4
6. Control the row electrode driver 47 and column electrode driver 48.

Here, a toner image was formed on the recording material P by setting the second control electrode 39 to 0 V and applying -500 V having the same polarity as the toner T to the first control electrode 37. When -200 V having the same polarity as the toner T is applied to the second control electrode 39 and -500 V having the same polarity as the toner T is applied to the first control electrode 37, no toner image is formed on the recording material P. Was.

According to the third embodiment, a printing state and a non-printing state can be realized by applying a voltage having the above-mentioned polarity. Therefore, the first and second control electrodes 3
The polarity of the power source of the voltage applied to the power supplies 7 and 39 can be shared, and the inexpensive printer 11 can be realized. Since the polarity of the applied voltage is the same as that of the toner T, unnecessary adhesion of the toner T to the electrodes 37 and 39 can be prevented.

The fourth embodiment is also similar to the first embodiment except that the polarity of the voltage applied to each of the control electrodes 37 and 39 is selected. The CPU 44 sets the first control electrode 37 to 0 V or selectively applies a voltage of −300 V, and sets the second control electrode 39 to 0 V or selectively applies a voltage of +200 V. Switching unit 4
6. Control the row electrode driver 47 and column electrode driver 48.

Here, the second control electrode 39 is set to +200 V having the opposite polarity to the toner T, and the first control electrode 37 is applied with -300 V having the same polarity as the toner T.
A toner image was formed on the recording material P. When the second control electrode 39 was set to 0 V and the first control electrode 37 was applied with -300 V having the same polarity as the toner T, no toner image was formed on the recording material P.

According to the fourth embodiment, a printing state and a non-printing state can be realized by applying a voltage having the above-mentioned polarity. Therefore, the first and second control electrodes 3
The electric field intensity required for printing can be obtained while suppressing the intensity of the voltage applied to 7, 39, so that the cost of the power supply can be reduced, and high security of the power supply can be ensured.
Further, since the polarity of the voltage applied to the first control electrode 37 on the toner transport belt 29 side is the same as that of the toner T,
Unnecessary adhesion of the toner T to the toner 7 can be prevented.

In the printer 11 of this embodiment, since the flying amount of the toner T is determined by the electric field intensity between the first and second control electrodes 37 and 39, a desired electric field intensity can be obtained. For example, any one of the second to fourth embodiments can be applied. Therefore, an optimal voltage application form can be selected according to the polarity of the toner T, the cost of the driver element which is the switching section 46 of the voltage applied to the control electrodes 37 and 39, the characteristics of the toner T, and the like.

FIG. 8 shows the evaluation results of the four types of toner T. Sample A had no external additive added to prevent the toner from falling off, Sample B had 0.5 part by weight of the external additive added, and Sample C had no external additive added.
The sample to which 0 parts by weight was added and the sample D were those to which 1.5 parts by weight of the external additive were added. Since the flying property of the toner T with respect to the electric field is stable even with a slight change in the composition of the toner, it can be seen that stable printing quality can be obtained over a long period of time if the electric field for the flying of the toner T is constant.

FIG. 9 is a diagram showing the first and second control electrodes 37 and 39 of the fifth embodiment. In the fifth embodiment, the positional relationship between the control electrodes 37 and 39 is selected. The first control electrodes 37a, 37b, 37c, 37d,.
m, and are arranged in a direction perpendicular to the recording material conveyance direction S1 with a gap of 140 μm. Each of the second control electrodes 39a, 39b,.
With respect to the direction in which the first control electrode 37 extends with a gap of μm (the direction perpendicular to the recording material conveyance direction S1),
The first control electrodes 37 are arranged so as to intersect with the first control electrode 37 at an intersection angle θ of 7 °.

Here, first, a drive voltage is simultaneously applied to the first control electrode 37a and the second control electrode 39a. Next, when the toner image d1 on the recording material P formed by the first control electrode 37a and the second control electrode 39a reaches the first control electrode 37b as the recording material P moves. , First
A drive voltage is applied to the control electrode 37b and the second control electrode 39a at the same time. Thus, a toner image d2 is formed on the recording material P next to the toner image d1. Similarly, as the recording material P moves, the first control electrodes 37c, 37d,
, And a drive voltage is applied to the second control electrode 39a. Thus, toner images d3, d4,... Are formed, and a straight line composed of toner images d1, d2, d3, d4,.

According to the fifth embodiment, the angle of intersection of the second control electrode 39 with the direction in which the first control electrode 37 extends, that is, the direction orthogonal to the conveying direction S1 of the recording material P, is 67 °.
By arranging the prints at the optimum resolution, it is possible to obtain a print with an optimum resolution.

It is preferable that the intersection angle θ be selected in the range of 45 ° <θ <90 °. If the crossing angle θ is 45 ° or less, the range of the electric field that reaches the toner T on the toner conveying belt 29 becomes narrow, so that a sufficient amount of toner cannot be obtained, and only low-resolution printing can be obtained. Also, the intersection angle θ
Becomes closer to 90 °, the distance between the first control electrodes 37 becomes longer, and it becomes difficult to maintain the distance between the control electrodes 37 and 39 with high accuracy. Therefore, it is particularly preferable that the intersection angle θ is around 63 °, at which a sufficient amount of toner can be scattered and the distance between the control electrodes 37 and 39 can be maintained with high accuracy.

In the sixth embodiment, the timing of the voltage applied to each of the control electrodes 37 and 39 is selected. Referring to FIG. 9, first control electrodes 37 a, 37 b, 37 c, and 37 d are applied to toner control belt 29 in the order opposite to conveyance direction S <b> 2, as shown in FIGS. period from t1 to t2, period from t3 to t4, t5 to t
A drive voltage of a rectangular wave, which is turned on with a shift in timing during a period from t6 to t8 and a period from t7 to t8, is sequentially applied. On the other hand, the second control electrodes 39a and 39b are
A drive voltage or a non-drive voltage that is turned on in each of the periods as shown in (e) and (f) is applied.

As a result, the drive voltages shown in FIGS. 10 (e) and 10 (f) can be selectively applied to the period from t1 to t2, the period from t3 to t4, the period from t5 to t6, and the period from t7 to t8. In a print state or a non-print state.
The waveform shown in FIG. 10 indicates the applied state of the signal, and does not indicate the magnitude or polarity of the applied voltage.

According to the sixth embodiment, each first control electrode 37
By selectively applying a driving voltage to the second control electrode 39 at a predetermined cycle and applying a driving voltage or a non-driving voltage to each of the second control electrodes 39, a charge uniformly acts on the toner T to be conveyed. Therefore, stable printing can be performed.

When the first control electrode 37 disposed on the side of the toner transport belt 29 is attached to the detachable toner supply unit 13 for replenishment and maintenance of the toner T, the voltage is controlled as described above. By applying the voltage, the number of control electrodes is reduced, and the reliability can be improved. The second control electrode 39 disposed on the recording paper P side
Is mounted on the main body of the printer 11, the second control electrode 39 is formed integrally with a driver or the like including an integrated circuit for applying a predetermined voltage to the control electrode according to an image signal on the electrode mounting substrate. can do.

In the seventh embodiment, the surface electric resistance of the toner conveying belt 29 is mainly selected. As a toner transport belt 29, carbon kneaded with polyimide 30
A μm thick belt is used. Such a toner transport belt 29 is arranged in contact with the first control electrode 37. A drive voltage is sequentially applied to each first control electrode 37 in a direction opposite to the transport direction S2 of the toner transport belt 29.
Thereby, the toner transport belt 29 is connected to the first control electrode 3.
7, and the toner image was formed stably on the recording material P. Further, in the vicinity of the toner transport belt 29, the contamination by the toner T was reduced.

Note that the above-described effect is obtained by
The surface electric resistance of the bolt 29 is 1 × 10 Ω · cm to 1 × 10
^TenObtained when the resistance is relatively high in the range of Ωcm
Was. The toner transport belt 29 is controlled by the first control
Conductivity not to be charged when sliding with electrode member 32
And when contacting the first control electrode 37
Excessive current flows through the toner transport belt 29
It is preferable to have such a surface electric resistance that
Typically 1 × 10⁶ Ω · cm to 1 × 10¹²Ω ・ cm range
It is preferable to have a surface electric resistance of

In this embodiment, an example is described in which the toner transport belt 29 made of a material obtained by kneading carbon with polyimide is used. In addition to this, for example, a material obtained by kneading carbon with polyester and a fiber having conductivity are used. A toner transport belt 29 made of a cloth material, a material having shrinkage obtained by kneading carbon with rubber, or the like may be used.

According to the seventh embodiment, the toner transport belt 2
9 can be brought into contact with the first control electrode 37 to improve the positional accuracy of the toner transport belt 29 and prevent the toner T carried on the recording material P from contacting with the recording material P due to the shake or vibration of the belt 29. Can be.

Further, since the surface electric resistance of the toner transport belt 29 is selected to be a relatively high value, the electrostatic attraction force of the toner T to the belt 29 increases due to the charging by the continuous rotation of the belt 29. The inconvenience that the flying property of the toner T decreases and the print density decreases can be prevented. Note that the surface electric resistance of the toner transport belt 29 is 1 ×
When the voltage is set to 10 ⁸ Ω · cm or more, a voltage corresponding to the applied voltage is applied
The current flowing through the control electrode 37 can be suppressed to such an extent that heat and the like are not affected, and charging of the toner transport belt 29 due to friction or the like can be prevented.

Further, by applying a drive voltage to the first control electrode 37 sequentially from the opposite direction to the transport direction S2 of the toner transport belt 29, the transport speed of the toner T can be apparently increased, and High-speed printing becomes possible.
However, the surface electric resistance of the toner transport belt 29 is 1 × 1
If it exceeds 0 ¹² Ω · cm, followability to the voltage applied to the belt 29 is reduced, and thus it is not suitable for high-speed printing.

In the eighth embodiment, the printing period in which the flying of the toner T is permitted includes a period in which a driving voltage is applied to the first and second control electrodes 37 and 39 and a period in which a non-driving voltage is applied. It was chosen. Referring to FIG.
The period from t1 to t3 is a printing state period, and the period is t.
It is configured to include a period in which a drive voltage is applied from 1 to t2 and a period in which a non-drive voltage is applied from t2 to t3.

According to the eighth embodiment, by including the period during which the non-driving voltage is applied in the printing period, the toner T flying toward the recording material P is affected by the next printing electric field. As a result, the print quality can be prevented from deteriorating, for example, the toner is deflected by the influence of the print electric field to shift the print position.

The first and second control electrodes 37, 39
Is a period during which the electric field strength for the toner T to fly toward the recording material P is minimum, and the toner T during the flight is not deflected. The period in which the drive voltage is applied to the first and second control electrodes 37 and 39 is the period in which the electric field intensity is at a maximum, but the voltage applied to the first and second control electrodes 37 and 39 is high. By shifting the timing of application, the rush current at the time of voltage switching can be dispersed, the capacity of the power supply can be reduced, and the wiring pattern can be miniaturized.

In the ninth embodiment, as shown in FIG. 11, the transfer of the drive voltage applied to the first control electrode 37 to the non-drive voltage in the eighth embodiment differs from that of the drive voltage applied to the second control electrode 39 in the eighth embodiment. This is performed before the transition to the non-drive voltage. According to the ninth embodiment, the drive voltage is applied to the second control electrode 39 longer than the first control electrode 37, so that the flying toner T reaches the recording material P without fail.
Therefore, the toner T scattered in the transport direction S1 of the recording material P can be suppressed.

In the tenth embodiment, as shown in FIG. 11, the transfer of the non-drive voltage applied to the first control electrode 37 to the drive voltage in the eighth embodiment is changed to the non-drive voltage applied to the second control electrode 39. Is performed prior to the transition to the drive voltage. According to the tenth embodiment, since an electric field acts on the toner T before the toner T flies, a voltage is applied to the second control electrode 39 and the toner T is smoothly applied.
Can fly. Therefore, printing with a uniform density in the plane can be performed.

FIG. 12 shows a second control electrode member 33 having a second control electrode 39 having a convex portion 58 according to the eleventh embodiment.
FIG. In the eleventh embodiment, the first control electrode 3
7 on the second control electrode 39, the first control electrode 37
, And a convex portion 58 is formed integrally. A second control electrode 39 having a projection 58 at a predetermined position is formed on the base 38, and a protective layer 59 is formed on the base 38 so as to cover them. Note that the surface of the projection 58 is exposed from the surface of the protective layer 59.

FIG. 13 shows the first and second embodiments of the eleventh embodiment.
It is a figure showing control electrodes 37 and 39. As shown in FIG. 13A, the first control electrodes 37a, 37b,
Are arranged in a direction orthogonal to the recording material conveyance direction S1. Second control electrodes 39a, 39b, 39 having a predetermined width
are arranged so as to intersect with the first control electrode 37 at a predetermined angle with respect to the recording material conveyance direction S1. The first control electrode 37 and the second control electrode 39 are opposed to each other with a predetermined distance.

According to the eleventh embodiment, as shown in FIGS. 13 (b) and 13 (c), a pixel having an area equal to the area of the projection 58 is formed regardless of the width of the second control electrode 39. be able to. Therefore, even when high-resolution printing is performed, the width of the second control electrode 39 itself can be widened, so that workability and reliability can be improved.

The twelfth embodiment is characterized in that an adhesive is applied to the surface of the recording material P on the toner transport belt 29 side.
Accordingly, repulsion and scattering that occur when the toner T lands on the recording material P, and dropping of the toner T that occurs before reaching the fixing unit 15 can be prevented, and high-quality printing can be performed.

When silicone oil is used as the adhesive, the adhesion of the toner T to the recording material P in the fixing unit 15 and the releasability from the heating roller 40 and the pressure roller 42 for fixing are improved. can do. Examples of the adhesive that can be used include liquids having an oily viscosity such as silicone oil and glue such as glue. The same effect can be obtained even with a liquid having almost no viscosity.

Finally, a printer according to a second embodiment of the present invention will be described. FIG. 14 is a cross-sectional view illustrating the vicinity of a printing unit of the printer according to the second embodiment. The printer is
This realizes color printing of a plurality of colors (four colors of Y (yellow), M (magenta), C (cyan) and K (black)) in the present embodiment, and is similar to the first embodiment. Four toner supply units 13a and 13 configured
b, 13c, 13d and four printing units 14a, 14
b, 14c and 14d. A single transfer belt 61 on which a toner image is transferred is commonly provided between the first control electrode members 32a, 32b, 32c, 32d and the second control electrode members 33a, 33b, 33c, 33d of each printing unit. Be placed. The transfer belt 61 is realized by, for example, a belt made of polyimide and having a thickness of 30 μm.
It is stretched on 63. Each toner image once transferred to the transfer belt 61 is transferred and fixed to the recording material P by a fixing unit including the roller 63 which is also a pressure roller and a heating roller 64 having a built-in heater 65. .

Each first control electrode member 32a, 32b, 32
In c and 32d, the first control electrodes 37 are arranged in parallel with each other. Each of the second control electrode members 33a, 33b, 33
In c and 33d, each second control electrode 39 is arranged in a direction intersecting with the opposing first control electrode 37. Also,
The transport direction S5 of the toner transport belt of each of the toner supply units 13a, 13b, 13c, and 13d and the transport direction S4 of the transfer belt 61 are selected to be opposite to each other. The transport direction S4 of the transfer belt 61 and the transport direction S3 of the recording material P are selected to be the same.

According to the printer of the second embodiment, color printing can be performed by transferring toners of different colors of Y, M, C, and K to the transfer belt 61 and then to the recording material P. As in the first embodiment, also in this case, high print quality can be stably obtained over a long period of time, high-resolution print quality can be obtained, and the assemblability and reliability of the printer can be improved. it can.

Note that the first to the first described in the first embodiment
Similar effects can be obtained by applying the second embodiment to the second embodiment. In the second embodiment, since a toner image is formed on the recording material P via the transfer belt 61, as described in the twelfth embodiment, an adhesive such as silicone oil is applied to the recording material P to improve the fixing property. Improving is particularly effective.

The printer described in this embodiment is used as a printing unit for data output of a computer, a word processor, or the like, or as a printing means of a digital copying machine or a facsimile machine. It is also suitably used for required devices and devices for forming color images.

[0115]

As described above, according to the present invention, since the toner carrier and the recording material are arranged between the first and second control electrode members, high print quality can be stably obtained for a long period of time. In addition, the control electrode member can be formed with high precision without being restricted by the thickness, and high-definition printing quality can be obtained. Further, the control electrode member is integrally formed with a control circuit and a driver to assemble the image forming apparatus. Performance and reliability can be improved.

Further, according to the present invention, a driving voltage having a polarity opposite to that of the toner is applied to the second control electrode member on the recording material side so that the toner on the toner carrier flies toward the recording material. A printing state is realized by applying the electric field between the first and second control electrode members, and a drive voltage having a polarity opposite to that of the toner is applied to the first and second control electrode members, so that the printing state is higher than during printing. A non-printing state can be realized by applying a weak electric field between the first and second control electrode members. Therefore, an inexpensive image forming apparatus can be realized by making the polarity of the voltage power supply applied to the control electrode member common.

Further, according to the present invention, a driving voltage having the same polarity as that of the toner is applied to the first control electrode member on the toner carrier side so that the toner on the toner carrier flies toward the recording material. A printing state is realized by applying an electric field between the first and second control electrode members, and a driving voltage having the same polarity as that of the toner is applied to the first and second control electrode members, so that the intensity is weaker than during printing. Of the first and second electric fields
A non-printing state can be realized by acting between the control electrode members. Therefore, it is possible to realize an inexpensive image forming apparatus by making the polarity of the power source of the voltage applied to the control electrode member common, and to prevent unnecessary adhesion of the toner to the control electrode member.

According to the present invention, a driving voltage having a polarity opposite to that of the toner is applied to the second control electrode member on the recording material side, and a driving voltage having the same polarity as the toner is applied to the first control electrode member on the toner carrier side. Is applied to the first and second electric fields so that the toner on the toner carrier flies toward the recording material.
A printing state is realized by acting between the control electrode members, and a voltage having the same polarity as that of the toner is applied to the first control electrode member, so that an electric field having a weaker intensity than during printing is applied to the first and second control electrode members. A non-printing state can be realized by acting between them. Therefore, it is possible to obtain the electric field intensity required for printing while suppressing the intensity of the voltage applied to the control electrode member, to reduce the cost of the power supply, and to ensure high security of the power supply. Unnecessary adhesion of toner to the electrode member can be prevented.

Further, according to the present invention, the electrodes of the second control electrode member are arranged at an intersection angle θ in the range of 45 ° <θ <90 ° with respect to the direction orthogonal to the conveying direction of the toner carrier.
Printing with the optimal resolution can be obtained. The intersection angle θ is
Particularly preferred is around 63 °.

Further, according to the present invention, a drive voltage is selectively applied to a plurality of electrodes of the first control electrode member at a predetermined cycle, and a drive voltage or a non-drive voltage is applied to the plurality of electrodes of the second control electrode member. Is applied, the charge uniformly acts on the toner to be conveyed, and stable printing can be performed.

Further, according to the present invention, the toner carrier is
By contacting the control electrode member, the positional accuracy of the carrier can be improved, and it is possible to prevent the carried toner from contacting the recording material due to the shake or vibration of the carrier. Further, by selecting the surface electric resistance of the toner carrier to a relatively high value, it is possible to prevent the print density from being lowered. Further, by applying a drive voltage to the plurality of electrodes of the first control electrode member sequentially from the direction opposite to the direction of conveyance of the toner carrier, the apparent toner conveyance speed can be increased, and high-speed printing can be performed. It becomes possible.

According to the present invention, the period of the printing state in which the toner is allowed to fly is constituted by the period in which the driving voltage is applied to the first and second control electrode members and the period in which the non-driving voltage is applied. Therefore, the toner flying toward the recording material is not affected by the next printing electric field, and it is possible to suppress a decrease in print quality due to a shift in a printing position or the like.

Further, according to the present invention, the transition of the drive voltage applied to the first control electrode member to the non-drive voltage is performed before the transition of the drive voltage applied to the second control electrode member to the non-drive voltage. As a result, the drive voltage is applied longer to the second control electrode member than to the first control electrode member, so that the toner in flight reliably reaches the recording material and scatters in the transport direction of the recording material. The amount of toner to be generated can be suppressed.

According to the present invention, the transition of the non-drive voltage applied to the first control electrode member to the drive voltage is performed before the transition of the non-drive voltage applied to the second control electrode member to the drive voltage. As a result, an electric field acts on the toner prior to the flight of the toner, and a voltage can be applied to the second control electrode member and the toner can fly smoothly, so that printing with a uniform density on the surface is possible. Becomes

Further, according to the present invention, since the convex portion directed to the first control electrode member is formed on the electrode of the second control electrode member that intersects with the electrode of the first control electrode member, the width of the second control electrode member is reduced. Irrespective of this, a pixel having an area equal to the area of the convex portion can be formed. Further, even in the case of performing high-resolution printing, the width of the second control electrode member itself can be formed wide, so that workability and reliability can be improved.

Further, according to the present invention, since the adhesive is applied to the surface of the recording material on the side of the toner carrier, the repulsion and scattering that occur when the toner lands on the recording material, and the falling off of the toner that occurs before the fixing process are performed. Can be prevented, and high-quality printing can be performed.

Further, according to the present invention, for example, color toner can be transferred to a transfer belt and then transferred to a recording material, thereby enabling color printing. Again,
High print quality can be obtained stably over a long period of time, and the control electrode member can be formed with high precision to obtain high-resolution print quality.Furthermore, the control electrode member is formed integrally with the control circuit and driver. Thus, the assemblability and reliability of the image forming apparatus can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a printer 11 equipped with an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a toner supply unit 13 of the printer 11;

FIG. 3 is a diagram illustrating a printing unit of the printer.

FIG. 4 shows a first control electrode member 32 and a second control electrode member 32 of the printing unit 14.
FIG. 4 is a cutaway perspective view showing a control electrode member 33 in an enlarged manner.

FIG. 5 is a block diagram of the printer 11;

FIG. 6 shows first and second control electrodes 37 and 3 of the first embodiment.
FIG.

FIG. 7 is a perspective view showing a second control electrode member 33 based on the first embodiment.

FIG. 8 is a graph showing a relationship between an electric field intensity formed between first and second control electrodes 37 and 39 and a print density on a recording material P;

FIG. 9 shows first and second control electrodes 37 and 3 of the fifth embodiment.
FIG.

FIG. 10 is a timing chart showing voltage application timings to first and second control electrodes 37 and 39 based on a sixth embodiment.

FIG. 11 is a timing chart showing timings of applying voltages to first and second control electrodes 37 and 39 based on a ninth embodiment.

FIG. 12 shows a second embodiment having a projection 58 based on the eleventh embodiment.
FIG. 4 is a perspective view showing a second control electrode member 33 provided with a control electrode 39.

FIG. 13 shows first and second control electrodes 3 of the eleventh embodiment.
It is a figure which shows 7,39.

FIG. 14 is a sectional view showing the vicinity of a printing unit of the printer according to the second embodiment.

FIG. 15 is a diagram showing electrodes for controlling the flight of toner in the image forming apparatus according to the prior art disclosed in Japanese Patent Application Laid-Open No. 54-134629.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Printer 12 Paper supply part 13 Toner supply part 14 Printing part 15 Fixing part 16 Control part 29 Toner conveyance belt 32 1st control electrode member 33 2nd control electrode member 36, 38 Base | substrate 37 1st control electrode 39 2nd control electrode 44 CPU (Central Processing Unit) 45 Voltage application unit 46 Switching unit 47 Row electrode driver 48 Column electrode driver 58 Convex part 61 Transfer belt

Claims (13)

[Claims] A first control electrode member including a plurality of electrodes; a second control electrode member including a plurality of electrodes facing the first control electrode; and a first control electrode member between the first and second control electrode members. A toner carrier that is arranged on the control electrode member side and carries and conveys charged toner; and a second control electrode member between the first and second control electrode members that conveys a recording material made of a dielectric material. A recording material conveying unit, wherein the plurality of electrodes constituting the first control electrode member are configured to fly a toner carried on the toner carrier to form a toner image on a recording material. The plurality of electrodes constituting the second control electrode member are arranged in parallel with each other, and are arranged in a direction intersecting with the electrode of the first control electrode member. The transport direction of the toner carrier and the transport direction of the recording material Is the opposite of Image forming apparatus characterized by chosen direction. 2. A voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage selecting means for selecting a voltage to be applied to the first and second control electrode members. Wherein a voltage to be applied to the second control electrode member and having a polarity opposite to that of the charged toner is selected to set a printing state in which the toner is allowed to fly, and the first and second control electrode members 2. The image forming apparatus according to claim 1, further comprising a voltage selection unit that selects a voltage having a polarity opposite to that of the charged toner and sets a non-printing state that inhibits the toner from flying. apparatus. 3. A voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage selecting means for selecting a voltage to be applied to the first and second control electrode members. A voltage applied to the first control electrode member, wherein a voltage having the same polarity as that of the charged toner is selected to set a printing state in which the toner is allowed to fly, and a voltage is applied to the first and second control electrode members. 2. The image forming apparatus according to claim 1, further comprising a voltage selection unit that selects a voltage having the same polarity as the charged toner and sets a non-printing state that inhibits the toner from flying. 4. A voltage applying means for outputting a driving voltage and a non-driving voltage applied to the first and second control electrode members, and a voltage selecting means for selecting a voltage to be applied to the first and second control electrode members. A voltage applied to the second control electrode member, the voltage having a polarity opposite to that of the charged toner, and a voltage applied to the first control electrode member, the polarity being the same as that of the charged toner. And a voltage applied to the first control electrode member, wherein a voltage having the same polarity as the charged toner is selected to prohibit the toner from flying. 2. The image forming apparatus according to claim 1, further comprising: a voltage selecting unit for setting a state. 5. The electrode of the first control electrode member is formed so as to extend in a direction perpendicular to the conveying direction of the toner carrier, and the electrode of the second control electrode member is an electrode of the first control electrode member. 2. The image forming apparatus according to claim 1, wherein the image forming apparatus extends at an intersection angle θ in a range of 45 ° <θ <90 °. 6. A first driving means for selectively applying the driving voltage to a plurality of electrodes constituting the first control electrode member at a predetermined cycle, and a plurality of the plurality of electrodes constituting the second control electrode member. 5. The image forming apparatus according to claim 2, further comprising a second driving unit that applies a driving voltage or a non-driving voltage to the electrodes. 7. The toner sheet according to claim 1, wherein said toner carrier has a surface electric resistance of 1
Is selected in the range of ^{× 10 6 Ω · cm~1 × 10} 12 Ω · cm, wherein the toner carrying member and the first control electrode member is disposed in contact with each other, said first drive means, the first control electrode 7. The image forming apparatus according to claim 6, wherein the drive voltage is sequentially applied to a plurality of electrodes constituting the member from a direction opposite to a conveying direction of the toner carrier. 8. A printing state period in which the flying of the toner is permitted includes a period in which a driving voltage is applied to the first and second control electrode members and a period in which a non-driving voltage is applied. 8. The image forming apparatus according to 7. 9. The transfer of the drive voltage applied to the first control electrode member to the non-drive voltage is performed before the transfer of the drive voltage applied to the second control electrode member to the non-drive voltage. The image forming apparatus according to claim 8, wherein 10. The transfer of the non-drive voltage applied to the first control electrode member to the drive voltage is performed before the transfer of the non-drive voltage applied to the second control electrode member to the drive voltage. The image forming apparatus according to claim 8, wherein 11. The method according to claim 1, wherein a convex portion facing the first control electrode member is formed on an electrode of the second control electrode member that intersects with the electrode of the first control electrode member. Image forming device. 12. The image forming apparatus according to claim 1, wherein an adhesive is applied to a surface of the recording material on the toner carrier side. 13. A plurality of first control electrode members each including a plurality of electrodes; a plurality of second control electrode members each facing the first control electrode members and each including a plurality of electrodes; A plurality of toner carriers each of which is arranged on the first control electrode member side between the two control electrode members and carries and conveys charged toner; and a second control electrode member side between each of the first and second control electrode members. A single transfer belt made of a dielectric material that is commonly disposed in the image forming apparatus; and a recording material conveying unit that conveys the recording material by contacting the transfer belt. In the image forming apparatus for forming a toner image by transferring the image on a transfer belt and then transferring the image onto a recording material, a plurality of electrodes constituting each first control electrode member are arranged in parallel with each other, Control electrode member The plurality of electrodes to be formed are arranged in a direction intersecting the electrodes of the first control electrode member facing each other, and the transport direction of each toner carrier and the transport direction of the transfer belt are selected in opposite directions. An image forming apparatus comprising: